Turbocharger Control Module: Description and Operation

Control Units:

PURPOSE
Turbo control unit includes the following basic functions:
1. Actuating fuel pumps
2. Switching supply voltage of oxygen sensor closed-loop control and acceleration enrichment
3. Switching supply voltage of ignition system
4. Switching ground for oxygen sensor heater
5. Switchover of oxygen sensor closed-loop control to open-loop control.

OPERATION
Prerequisites for function 1:
^ Terminal 15 ON and engine speed signal from EZ control unit or terminal 50 present
^ Engine speed below 6750 rpm
^ Boost pressure cutout switch closed

Prerequisites for function 2:
^ Terminal 15 ON
^ Engine speed below 3000 rpm

Prerequisites for function 3:
^ Terminal 15 ON


Prerequisites for function 4:
^ Only if oxygen sensor closed-loop control is activated

Prerequisites for function 55:
^ If oxygen sensor closed-loop control is not activated.

Turbo control unit also handles:

^ Voltage supply to:
- Control pressure regulator
- Auxiliary air regulator
- Frequency valve
- Oxygen sensor heater

^ Safety circuit for fuel pumps
^ Boost pressure safety circuit
^ Ignition delay relay